1)Dr. Aravind and his group analyzed DBC1 and its homologs to suggest a potential mechanism for regulation of sirtuin domain deacetylases by NAD metabolites. Deleted in Breast Cancer-1 (DBC1) and its paralog CARP-1 are large multi-domain proteins, with a nuclear or perinuclear localization, and a role in promoting apoptosis upon processing by caspases. Recent studies on human DBC1 show that it is a specific inhibitor of the sirtuin-type deacetylase, Sirt1, which deacetylates histones and p53. However, the exact mechanism of action of these proteins has largely remained mysterious. Using sensitive computational methodss we show that the central conserved globular domain present in the DBC1 and CARP-1 is a catalytically inactive version of the Nudix hydrolase (MutT) domain. Given that Nudix domains are known to bind nucleoside diphosphate sugars and NAD, we predict that this domain in DBC1 and its homologs binds NAD metabolites such as ADP-ribose. Hence, we developed a model that DBC1 and its homologs are likely to regulate the activity of SIRT1 or related deacetylases by sensing the soluble products or substrates of the NAD-dependent deacetylation reaction. The complex domain architectures of the members of the DBC1 family, which include fusions to the RNA-binding S1-like domain, the DNA-binding SAP domain and EF-hand domains, suggest that they are likely to function as integrators of distinct regulatory signals including chromatin protein modification, soluble compounds in NAD metabolism, apoptotic stimuli and RNA. The prediction of a soluble low molecular weight ligand for DBC1 also opens the possibility for developing new therapeutics based on soluble small molecules. 2)In conjunction with Dr. K. OConnells group at NIDDK Dr. Aravind showed that the conserved predicted RNA-binding protein SZY-20 opposes the Plk4-related kinase ZYG-1 to limit centrosome size. Microtubules are organized by the centrosome, a dynamic organelle that exhibits changes in both size and number during the cell cycle. The maintenance of appropriate centrosome size is critical for proper cell division and partitioning of biomolecules and organelles between the daughter cells. However the exact mechanism by which this process is regulated is unclear. Here we show that SZY-20, a predicted RNA-binding protein, plays a critical role in limiting centrosome size in the nematode worm C. elegans. Homologs of SZY-20 are present throughout eukaryotes pointing to conserved role for this protein. SZY-20 localizes in part to centrosomes and in its absence centrosomes possess increased levels of centriolar and pericentriolar components including gamma-tubulin and the centriole duplication factors ZYG-1 and SPD-2. These enlarged centrosomes possess normal centrioles, nucleate more microtubules, and fail to properly direct a number of microtubule-dependent processes. Depletion of ZYG-1 restores normal centrosome size and function to szy-20 mutants, whereas loss of szy-20 suppresses the centrosome duplication defects in both zyg-1 and spd-2 mutants. Our results thus describe a pathway that determines centrosome size and implicate centriole duplication factors in this process. Computational analysis showed that SZY-20 contains a two novel protein domains the SUZ and SUZ-C domain which are predicted to be respectively critical for RNA-binding and targeting of ribonucleoprotein complexes. It was also shown to be a part of a large complex of RNA-binding proteins. Mutagenesis of conserved residues in these domains result in loss of SZY-20 function and loss of ability for form RNA-protein complexes. The presence of a RNA-binding domain in SZY-20, a centrosomal protein, suggests that it might be key for partitioning of RNA during cell division. Furthering our understanding of centrosomal development is critical for discovering the biological bases of several human diseases. Given that SZY-20 is a conserved protein with a cognate in human this finding might help in investigating key processes relating to centriolar development in humans. 3)Dr. Aravind in collaboration with Dr. Sanjay Kumars lab at FDA/NIAID initiated a major project to study the pathogenesis of cerebral malaria using a combination of computational and experimental tools. Dr. Aravinds group performed the computational analysis for the discovery of host biomarkers and biological pathways associated with the expression of experimental cerebral malaria in mice. Cerebral malaria is a primary cause of malaria-associated deaths, especially in sub-Saharan Africa. There is very poor understanding of the molecular profile of the progression from Plasmodium falciparum regular malaria to CM. This hampers the development of prognostication tools for this condition. To this end we used the Plasmodium berghei ANKA murine model of experimental cerebral malaria and high-density oligonucleotide microarray analyses to identify host molecules that are strongly associated with the clinical symptoms of this condition. Comparative expression analyses were performed with C57BL/6 mice, which have an experimental cerebral malaria (ECM)-susceptible phenotype, and with mice that have ECM-resistant phenotypes: CD8 knockout and perforin knockout mice on the C57BL/6 background and BALB/c mice. These analyses allowed the identification of more than 200 host molecules (a majority of which had not been identified previously) with altered expression patterns in the brain that are strongly associated with the manifestation of ECM. Among these host molecules, brain samples from mice with ECM expressed significantly higher levels of p21, metallothionein, and hemoglobin alpha1 proteins by Western blot analysis than mice unaffected by ECM. The higher expression of hemoglobin alpha1 in the brain may be associated with ECM and could be a source of excess heme, a molecule that is considered to trigger the pathogenesis of CM. Our studies greatly enhance the repertoire of host molecules for use as diagnostics and novel therapeutics in CM. This study is the first systematic attempt to tackle the issue of potential molecular markers to understand the progression of cerebral malaria. The results from it help in understanding certain major features that trigger morbidity in cerebral malaria and offers potential leads for its prognostication and development of new therapeutics.